Laparoscopic surgery is gaining prominence as the preferred surgical method since the time required for recovery and the risk to the patient are less than with conventional surgical procedures. In laparoscopic surgery, all surgical instruments are inserted through tubes, or trocars, which are placed in small incisions in the abdomen. These small incisions are less susceptible to wound infections and take much less time to heal than the single large incision usually made with conventional techniques. Also, since a large surgical area is not exposed during laparoscopic surgery, the incidence of internal infection is also reduced.
Laparoscopic surgical procedures require that a gas, such as carbon dioxide, be introduced into the abdominal cavity. This establishes pneumoperitoneum wherein the peritoneal cavity is sufficiently inflated for the insertion of trocars into the abdomen. The distal end of the trocars move within the gas-filled cavity and thus provide access to an area larger than the small incision through which the trocar is inserted. During laparoscopic surgery, the flow of gas into the peritoneal cavity continues to replace any gas that is absorbed by the patient or which leaks out through the trocars.
Pneumoperitoneum is established through the use of a special insufflation needle, called a Veress needle, which has a spring-loaded obturator that advances over the sharp tip of the needle as soon as the needle enters the abdominal cavity. This needle is inserted through the fascia and through the peritoneum. Generally, the surgeon relies on tactile senses to determine the proper placement of the needle by recognizing when the needle is inserted through the fascia and then through the peritoneum. However, this technique is often unreliable for a thin patient whose fascia and peritoneum feel like a single layer.
The proper placement of the Veress needle is critical. First, the needle must go through both the fascia and the peritoneum. If the needle is inserted between the fascia and the peritoneum, massive distention of the preperitoneal space therebetween will result. If the needle goes beyond the peritoneum, the needle may perforate the stomach, small bowel, colon, bladder, or major vascular structures, the consequences of which can be fatal. The purpose of the spring-loaded safety tip of the Veress needle is to minimize the risk of visceral injury by covering the sharp tip once it has penetrated the peritoneum. However, in order for the safety tip to be extended, the tip of the needle must reach a void with the tissue. Such a void may not exist for a patient having excessive fat in the abdominal cavity. Thus, it is desirable to utilize a device and a method whereby the insertion of the device can be seen by the surgeon to avoid misplacement of the sharp point of the device.
Present methods for establishing pneumoperitoneum through the use of a Veress needle work very well in normal sized people who have not had previous surgery. They do not work well for those patients who are obese, that have previously had surgery, peritonitis, or severe inflammation. There are also problems in using these methods for patients who have cancer which has spread along the peritoneum. For example, if the patient previously had surgery or has cancer, the intestines may be stuck to the peritoneum with dense fibrous adhesions. In these patients, the needle may go through the peritoneum into the lumen of the bowel.
After establishing pneumoperitoneum, the next step in laparoscopic surgery involves the insertion of a trocar into the abdominal cavity. It is through this first trocar that an endoscope is inserted into the abdominal cavity to provide the surgeon with a view of the rest of the operation. Trocars are similar to the Veress needle in that they are also equipped with a spring-loaded safety shield to avoid visceral injury. Trocars, like Veress needles, are inserted using a sudden thrust of the pointed tip into the abdomen. Therefore, as is true with the Veress needle, placement of the trocar is also vital, and the reliance of the surgeon on mere tactile senses for proper placement can be fatal. In using the current methods, once the endoscope is in place, all other trocars used to perform the remainder of the surgical procedure are visible through the endoscope once they reach the abdominal cavity, and, therefore, their insertion is usually safe. It would be desirable, however, to also provide a visualization system in which the potential hazards associated with the insertion of the first trocar are avoided.
Endoscopes are used in a variety of surgical procedures to provide the surgeon with visual information not otherwise available. For example, the endoscope disclosed in U.S. Pat. No. 4,607,622 is used in treating, diagnosing and investigating problems with the eye. In light of its intended purposes, this endoscope provides an appropriately shaped probe which is able to receive other instruments for the purpose of treating the eye while the instrument is in the view of the endoscope. Similarly, the laser endoscope disclosed in U.S. Pat. No. 4,211,229 allows a laser instrument or other surgical device to be interchanged within the sheath of the endoscope. Disclosed in U.S. Pat. No. 3,941,121 is an endoscope through which an electrode may be inserted.
In the development of endoscopes, the provision of viewing both forward and to the side is disclosed in U.S. Pat. Nos. 3,856,000 and 3,880,148. Binocular vision, and thus improved depth perception, is provided for in the invention disclosed in U.S. Pat. No. 4,061,135 which also provides a cauterizing loop at the forward end of the endoscope. The endoscope disclosed in U.S. Pat. No. 3,941,121 may be focused to provide both microscopic and telescopic vision to the surgeon. Furthermore, the size of the endoscope in U.S. Pat. No. 3,941,121 is such that it may be inserted into a very small sheath since the device is only 18-gauge or smaller.
Many endoscopes are inserted through a sheath or tube inserted into an incision in body tissue. Thus, blindly creating an incision for the placement of a sheath can result in potential problems for many types of surgery in which an endoscope is used, not just laparoscopic surgery. It is desireable to provide an endoscope which does not require that a preliminary incision be made for placement thereof (except for an optional skin incision).
The needle endoscope disclosed in U.S. Pat. No. 3,941,121 is small enough that it may be used without a sheath and therefore avoids the need to create a preliminary incision before its insertion. However, as stated above, the insertion of this needle endoscope as well as insufflation needles and trocars ordinarily used in laparoscopic surgery require that the surgeon push the instrument into the abdomen. The force required to do so may result in the inadvertent placement of the instrument beyond the desired location and perhaps even into an organ or a major vascular structure. Thus, it is desireable to provide a method for laparoscopic surgery in which less force is required and greater control of the forward end of the instrument is achieved to thereby further reduce the risk of the procedure to the patient.